Security readout for executives and security teams
Plain-English summary
This old Cisco IOS issue can let a low-privileged user crash an affected router or network device after reaching an interactive prompt. The business impact is mainly temporary availability loss, not data theft or integrity compromise. Exposure depends on whether any legacy IOS 9.x, 10.x, or 11.x devices remain reachable.
Executive priority
Treat this as a legacy hygiene and availability risk. It is not high urgency unless old IOS devices protect critical network paths or prompt access is broadly reachable.
Technical view
CVE-1999-0159 is a Cisco IOS denial-of-service condition mapped to CWE-400. The record says some IOS 9.x, 10.x, and 11.x releases can be crashed by an attacker who reaches an interactive prompt, such as a login. CVSS 3.1 is 3.5 with low availability impact.
Likely exposure
Most modern environments should have low exposure unless they still operate legacy Cisco IOS 9.x, 10.x, or 11.x devices. The source bundle does not provide exact affected releases, CPEs, or fixed versions.
Exploitation context
No provided source or KEV listing supports active exploitation. The attack requires access to an interactive prompt, so exposure is narrower than unauthenticated internet-facing denial of service.
Researcher notes
The public data is sparse: affected product fields are not normalized, exact releases are not listed, and no patch details are supplied. Keep analysis bounded to prompt-reachable denial of service on some IOS 9.x, 10.x, and 11.x releases.
Mitigation direction
- Inventory Cisco devices for IOS 9.x, 10.x, or 11.x releases.
- Restrict router interactive prompt access to trusted administrators only.
- Check Cisco or vendor guidance for fixed or unaffected releases.
- Isolate or retire unsupported legacy IOS devices where practical.
- Monitor affected device classes for unexpected crashes or reloads.
Validation and detection
- Confirm whether any Cisco IOS 9.x, 10.x, or 11.x devices remain in service.
- Review who can access interactive prompts on legacy routers.
- Check device logs for unexplained reloads or crash events.
- Compare observed versions against vendor guidance when available.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-1999-0159 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Low
- CVSS
- 3.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L2.11.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
3.5LowVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0159CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.